Chris,

I wrote a thesis on the types, and chemical analysis of bloomery slag 
from a site in Negaunee, Michigan. It includes images of the different 
forms of slag found, and of one type of hammer scale (spheroidal) and 
the problem associated with recovery. In a discussion I had after 
writing the thesis, a current smelter of bloomery iron mentioned that 
much of the slag produced from refining would visually resemble that 
resulting from bloomery smelting.

The chapter on slag might be small enough to email (about 1 MB). Please 
contact me off-list if you're interested. In addition, you might find 
the datasheets (available online) from the Historical Metallurgy 
Society helpful.

Tim Mancl, RPA
Heite Consulting

On Apr 26, 2006, at 7:17, Christopher Murphy wrote:

> James,
>     Your post sounds like a concise, brief summary of iron working in 
> the late 18th and early 19 centuries.  I would like to learn more 
> about recognition of things such as hammer scale, fayalitic slag, etc. 
> Is there a source or series of sources you could post to the list 
> which would
> bring those of us only vaguely familiar with the process, products, 
> and by-products up to speed (or at least closer)?
>
>     Chris Murphy
>     Augusta State University